Power take-off joint assembly



NOV- 24, 1942 c. E. swENsoN PWER TAKE-OFF JOINT ASSEMBLY md May 29. 1941 J4 13 49 fffz if Patented Nov. 24, 1942 UNITED STATES"PATENT `OFFICE POWER TAKE-OFF JOINT ASSEMBLY Carl E. Swenson, Rockford, Ill.

Application May 29, 1941, Serial No. 395,731

(Cl. 18o-14) Claims.

This invention relates to power take-off assemblies for tractors and similar devices for use in driving vehicles trailed therebehind, and has special reference to a universal joint mechanism for driving a driven shaft connected to said vehicle, together with means for supporting the same and controlling the operation thereof. This is a continuation in part of my copending application Serial No. 359,017, led September 30, 1940.

Substantial diiculty is now encountered in the eld of power-driven farm implements, and doubtless in numerous other analogous fields, due to the dilliculty in connecting the implement to a tractor. There is wide variation between the tractors of different manufacturers, in the relative locations of the power take-off shaft and the hitch point, these diiferences doubtless being due to differences in structure and design of the tractor mechanism. As a result of these variations, it is necessary for each manufacturer of power-driven implements to provide a wide variety of tow bar and implement drive mechanism designed to t the implement to different tractors. This requires the manufacturer and dealer to stock a large number of parts for attachment of each vehicle to the different tractors, and results in considerable confusion and a substantial amount of trial and error in adapting the implement to any given tractor. Furthermore, it requires the user to have on hand a substantial number of dilerent assemblies for use on different implements. These difculties arise from the necessity of maintaining the universal joints of the drive mechanism and the pivot point of the hitch mechanism in certain relationships to give substantially constant angular velocity to the shafts when using the Cardon type joints ordinarily used, and the necessity for supporting the shaft connecting the tractor with the implement.

An important object of the invention is the provision of a power take-off assembly supported wholly upon the tractor, and in effect forming a part thereof so arranged that the pivot pin of the draw bar can be located at any convenient` place at the rear of the tractor, the assembly forming in effect a continuation of the power take-off shaft to provide a power take-off shaft capable of driving at any angularity with respect to the tractor within the normal range of operation, such that a uniform drive shaft and tow bar construction can be used on the trailing implement.

Another important object of the invention is sembly of novel and improved construction adapted to effectively become a part of the tractor.

I have also aimed to provide a power take-01T mechanism including a pair of close coupled universal joints in which the rear end of the mechanism is supported in xed relationship with thev driven shaft, wherein the joints are supported so that the angularity between the shafts is substantially equally divided between the two joints to give substantially constant angular velocity to the driven shaft, and wherein a sliding driving connection is provided between the forward end of the mechanism and the tractor shaft to accommodate for differences due to angularity between said shafts.

A further object of the invention is the provision of a power take-olf mechanism including close coupled universal joints wherein the mechanism is supported on a vertical axis in a bearing occupying a fixed relation with respect to thel driving shaft and is pivotally supported on a horizontal axis disposed rearwardly of the pivot plane of the rear universal joint, and a slidable driving connectionis provided between the drive shaft of the tractor and the front universal joint.

A still yfurther object of the invention is .the provision in a tractor of power take-off mechanism wherein novel supporting means is provided to impart greater rigidity to said mechanism against lateral force and to reduce the chatter or vibration due to angularity of the shafts.

In order to transmit uniform angular motion from a driving to a driven shaft, two closely coupled universal joints may be employed together with means for maintaining the angularity of the two joints substantially equal, and it is an object of the invention to provide in a tractor, such a combination wherein the joints are supported for angular movement on a vertical axis forwardly of the center of the coupling member and on a horizontal axis disposed rearwardly of the center of the rear joint whereby to obtain maximum angular movement between the shafts and at the same time obtain substantially constant angular velocity of the driven shaft and the maximum rigidity of support.

A still further object of the invention is the provision of a joint assembly wherein the rear joint and the supporting bearing therefor are supported in iiXed relation to both the vertical and horizontal axes to make the joint assembly entirely independent of the trailing implement.

the provision in a tractor' of a power take-olf as- 55" A further object of the invention is the pro vision of a power take-off joint assembly for tractors wherein the joints are supported for rotation and angular movement at a point adjacent the junction between the joints and the driven shaft and for slip movement on the driving shaft.

Another object of the invention is to provide a device of the character described wherein the joints are supported on a vertical axis fixed with respect to the tractor, and means are provided between .the joints andthe driving shaft for taking the slippage necessitated by angular movement of the joints so as to reduce the vibration,

wear and power loss to a minimum, and also to v reduce the overall length of the device.

Another object of the invention is to providey a structure of the character described in whichthe secondary loads due to the joints and reacting on the shafts can be supported close to the pivot points to avoid chatter and vibration therein due to exing in the supports.

A further object of the invention is the provision of a structure of the character describedhaving improved means for supporting the forward joint so as to substantially shorten the assembly and impart greater rigidity thereto by improved support of the forward yoke, the forward yoke being supported in an annular bearing in close proximity to the adjacent joint.

Other objects and advantages will become apparent from the following description and the accompanying drawing, in which- Figure 1 is a side view partly in section showing a power take-off assembly embodying my invention;

Fig. 2 is a. top View thereof, and

Fig. 3 is a view on the line 3 3 of Figure l.

In the drawing the numeral 5 designates a portion of the conventional frame structure oi a tractor or the like, this commonly being a part of the gear housingV through which a shaft 6 projects inthe form of a stub shaft and constituting a power take-off shaft from the tractor. According to the invention this shaft is splined as indicated at 1, in this instance the splines extending from the outer end thereof inwardly to a point beyond the housing 5, the housing having an opening 8 around the shaft.

Close coupleduniversal joints, indicated generally at 9 and I I, are arranged to be driven from the driving shaft 6 and may be of any of the well known types, in this instance they are of the so-called Cardon type and comprise a pair of yokes I2 and I3 disposed in coplanar relationship, the yoke I2 comprising an internally splined sleeve I4 and yoke arms I5, the latter vbeing pivotally connected to a spider l@ which is in turn pivotally connected to spaced ears I1 on a transmission ring I8, the transmission ring having spaced ears I9 for pivotal attachment to a spider 2| to which yoke arms- 22 of the yoke I3 are pivotally attached. It will be seen that the yoke I2, spider I6 and spaced ears I1 form one universal joint, while the yoke I3, spider 2| and ears I9 form a second universal joint, the two being connectedA by the transmission ring I8 which forms a transmission member between the two joints.

The internally splined sleeve I4 of the yoke I2 receives the driving or power take-off shaft 6 of the tractor, the interconnecting splines of the shaft 6 and sleeve I4 serving to transmit rotary motion from theshaft to the joint 9 and simultaneously permitting relative longitudinal movement between the shaft and the sleeve. The opening in the end of the sleeve I4 is closed by a cap 23 to prevent the entrance of dirt and foreign matter into the slidable driving connection between these elements. It will be understood that while the connection between the sleeve I4 and the shaft 6 is described and herein shown as a conventional spline connection, this may be any connection which will transmit rotary motion from the shaft to the yoke and will permit relative longitudinal movement between these members, many equivalent connections being well known in the art.

The yoke I3 of the joint II is also provided with an internally splined sleeve 24 adapted to receive the splined end of the driven shaft 25. It is contemplated that the driven shaft 25 shall be the shaft connecting the tractor with the trailed implement and functions for the purpose of providing a power drive for the mechanism carried on the implement. Commonly these driven shafts are connected to the gear box of the implement through a universal joint, and the shafts themselves are formed of telescoping parts so that the effective length thereof is automatically changed in response to angular movement between the tractor and the implement, all of which is well known in the art. The sleeve 24 and the shaft 25 are provided with openings for the passage of a bolt 26 which acts to fix the shaft to the yoke in relatively immovable relationship. It will be seen that many means may be employed for making this connection, but I prefer to employ some means whereby the shaft and the yoke may be easily disconnected for convenience in attaching the assembly to different trailing vehicles, and for this purpose the bolt and spline connection is suitable, though other satisfactory connections are knownin the art.

It will be seen that the mechanism heretofore described acts to transmit the power from the driving shaft 6 to the forward end of the driven shaft 25, and permits of relative angular movement between the two shafts. However, means must be provided for supporting the joint andv for causing the angular motion between the shaft to be properly distributed. This construction includes a support member designated generally by the numeral 21, in this instance the member being in the form of a sleeve 28 having out-l wardly disposed arms 29 and 3|, the sleeve 28 encircling the-driving shaft 6 in concentricrelationship therewith. The support member has a flange 32 adapted for attachment of the support member to the frame 5 in rigid relation therewith, and the support member is provided with reinforcing ribs 33 of conventional design.y 'Ihe outer ends of the arms 29 and 3| are provided with threaded openings 34 for the reception of bearing members 35 and 36 having frustoconical bearing surfaces 31 and 38 received in complementary openings in the ends of fingers 39 and 4I, which are in turn attached to a co1- lar 42, the fingers 39 and 4I and the complementary bearing surfaces providing for rotation of the collar about a vertical axis through the bearing members 35 and 36. The collar 42 has at opposite sides thereof frusto-conical bearing surfaces 43 and 44 adapted to receive complementary bearing surfaces on bearing pins 45 and 46 positioned in openings on the ends of ears 41 and 48, in this instance .integral with a bearing housing 49 extending annularly of the yoke sleeve 24. The bearing members 35, 36, 45 and 46 are secured in their respective openings by 7&3 means of bolts such as shown at 5I passing Kthrough 1 opposed "sides of fspl-it rings lforrning the 'fendso'ffarms and 3'Ia'i1dears4l andiand forni-ing fthe openings "for-the reception `'of the `bearing .members as 'is well known "in the 'art Positioned Within the lhearing `housing 49 is la bearing consisting in Ithis rinstance of an i'n-'n'e'r rac'ef52fsea'tedon th'e 's1eevei24 and held against longitudinal movement by a snap 'ring 53 "or i'other suitable means. A'n :outer race y"54 bears against 'the bearing housing, fand an annulus -o'f balls 55 is disposed therebetween l'inthe 'convene tional fashion. While this bearing fin 'this inis'tan'ce mounted onthe sleeve of the yoke I3, it `Will 'be `"understood that this bearing "Cali b `mounted on `the shaftl215 if desiredgthe essential ilo 'thing being that the bearing be `mounted rea-'rwardlyof Vthe 'rearward joint so -as to 'support 'the universal joints fat this' point and also y-so `as to .support the 'driven fshaft. Numerous altera- 'tions inlay 'be made lin which the bearing may have Vdifferent 'mountings Vbut lit is contemplated that these shall be jeq'uivalent constructions zwhere the functions described Yare performed. lIt 'will also be -seen that a further function of 'this lbearing is to prevent longitudinal Amovement 1 of 'the yoke 24 and to require -the longitudinal movement necessitated by rotation of the joints about the vertical aXi's to occur between 'the sleeve 14 and the shaft 6. The particular ar- .rangement of the bearing fand sleeve 2f'4 i`s .of 'merit in that it maintains Ithe Overall length "0i the joint assembly at a minimum and 'permits of convenient removal and vreplacement of 'the 'sl'laft25- Bearing means is disposed between the 'yoke sleeve |4 'and the support sleeve 28 for the pure pose'of guiding and supporting the 'forward 'yoke fso as to prevent lateral movement o'f the yoke vand prevent chatter and similar loss of energy at this point. This bearing in this instance iniclud'es an in'ner race 56 vsecured to the yoke to prevent the entrance of dirt into the bearing between the piston and the cylinder 28. t will be seen that as the yoke moves longitudinally on the shaft 5, the piston-like member 59 will slide in and out in the sleeve 28 and impart lateral support to the yoke, regardless of its position. It will also be noted that this bearing provides support for the forward end of the universal joint assembly in close proximity tothe joint so as to reduce to a minimum any vibration which might tend to be set up by laterally directed forces. The opening!! around the :shaft 5 permits of movement of the yoke sleeve I4 through the frame 5 in extreme movements. of

the yoke. This construction permits the length of the joint assembly to be reduced to a lrlini mum, and provides for a high degree' of lateral support. y

In the operation of the devi-ce, all of theinechanl'sm except the shaft 25 is permanently at? tached to the frame of a tractor so thatinelect the sleeve 24 forms a universal power take-off shaft for the tractor so that the connecting shaft of any trailing vehicle may be connected to this' sleeve and proper drive conditions result. In this wey, the multiplicity of devices heretofore used for transmitting power lfroii the tractor' 'to' the trailing vehicle is eliminated, 'and this A le 'power take-off assembly provides a universal drive for all implements. As heretofore 'dee' 'Seribfl` in use theshaft 250i the trailing iinplein'ellt is 4'il'edly attached to the lsleeve 24h37 the `D`O1t 26, the conventional hitch '0f the trailer is 'attached to the Hitch 0f the tractor,V and the cOnl; bloed device is ready for operati-bil. It will be 'Seen that the support for the universal joint as'e `sel'nbly` and for the driven shaft is vessentially through the' bearing 55, the ears 4T and 48, the 'collar 1522, lingers `39Vand 4I, and support member 21 to the frame of the tractor. Rotation of th drive shaft "5 causes rotary motion to be transmit# @ed enroll-ghehe l2, the spider ls, the trans-y mission anelli, the spider 2l, and the 'yoke le to the` driven shaft 25. It will be Se'n that when a turning movement occurs as between the trac'- torand the trailing implement, ar'lgularit'yfclevelops between the driving shaft 6 and the driven shaft 25, the bearing 55 i'novig with the's'haft 2'5 through rotation of the lingers 39 and 4l about the center of tbeV bearing members se 'elle 3s,

longitudinal movement simultaneously occurring y yokes l2 and i3 with respect to the axis of rol-.elll-- tion of the transmission 'ring will be Substantially equal, /S' will b'e' ysoleil 'roirlFig 2.-

tive angular movement between4 the shafts' in a, vertical plane and arejlocated slightly to the rear i of tbe axis' ofthe splde'rtl to thereby provide s maximum degree of angular displacement btweenthe shafts in' a horizontal plane. It'will 15e" understood that'tfle relative' angular Il'lovi ments of -the shafts in a vertical plane isno rmally aused by uneveniie'ss or variation in they surface 'of the ground .over which the tractor and implement travel; Since l these variations are relatively Small; comparatively small differences inangularity will exist and the pivotal support for'such movement can therefore-be located rear wardly of the spider 2l to obtain the advantages above described. 4 l

Attention is directed to the fact'th'at4 the -sliding movement in the drive system occasioned by angular movement of the shafts is taken' between the drive Shaft 6 and the 'sleeve M directly acl-'- jacent the frame` Of the tractor in which the lo'osel'less necessitated by the sliding nt produces e minimum of shatter snol lateral movement of Y fit on permanently" located with respect" to the diiv Siift aild the ydke i3 andisrstlpported nvclo's'e' proximityl to the pivot points, a riiore 'rigid and smooth running structure is 'provided'. Furthermore, this permits the bearing to be brought closer tothe center of the joint andvits supports; Another` feature of the invention is tile feet that the only relative movementcoeur-- nog between'tlle sleeve I4 and the shaft t ls lone gltuclinel movement, whieh movementlsrela*-y tively small in degree-and does .not cause substantial Wear in case the complemental surfaces become contaminated with dirt, as would be the case should rotary motion also be present in this connection.

An important feature of the invention is in the .provision of longitudinal sliding movement disy sal joints, which makes it unnecessary to havethe draw bar pivot pin substantially half-way between the joints, which is necessary with present common practice, in order to obtain substantially constant angular velocity in the driven shaft.

While I have described and illustrated a specific embodiment of the invention, I do not wish to be limited except as required by the scope of the appended claims, in which- I claim:

1. The combination with a tractor of a power take-ofi assembly for driving a trailing vehicle comprising a driving shaft on said tractor, a driven shaft adapted for transmitting power drive for mechanism carried on the trailing vehicle, a pair of close coupled universal joints having a forward yoke for driving connection to said driving shaft and a rearward yoke for driving connection to said driven shaft, means xedly attached to the tractor for supporting said rearward yoke to rotate on an arc of a circle about a fixed vertical axis with change in angularity of said shafts in a horizontal plan'e, a sliding driving connection between saidv forward yoke and said driving shaft for relative longitudinal movement therebetween with change in angularityof said shafts, and a Yiixed driving connection between said rearward yoke and said driven shaft. 2. The combination in a tractor power takeoff assembly providing a close coupled drive unit between a driving shaft on the tractor and a driven shaft adapted for transmitting the drive to mechanism carried on a trailing vehicle, of a pair of close coupled front and rear universal joints, the front universal joint having a sliding driving connection with said driving shaft for longitudinal movement with respect thereto, the rear universal joint having a yoke shaped for connection to said driven shaft, a bearing supported on said yoke in longitudinally xed relation thereto for support of said joints, and means positioned in fixed relation with said driving shaft for supporting'said bearing for rotation about a horizontal and a vertical axis with relative angular movement of saidy yoke and said driving shaft.

-3. The combination with a tractor of a power take-off assembly for driving a trailing vehicle comprising a driving shaft on said tractor, a driven shaft adapted for transmitting power drive for mechanism carried on the trailing vehicle, a pair of close coupled Cardan type universal joints having a forward yoke for attachment to said driving shaft and a rearward yoke for attachment to said driven shaft, means forming a fixed part of the tractor and including a bearing for supporting said rearward yoke for rotation on the arc of a circle about a fixed vertical axis disposed adjacent to the mid-point between said joints with change in angularity of said shafts in a horizontal plane to keep the angles between said joints approximately uniform at all relative positions of the tractor and trailing vehicle, said means including pivots for supporting said bearing for rotation on a horizontal axis, said bearing being fixed longitudinally with respect to said rearward yoke and said driven shaft in all positions, and a sliding driving connection between said forward yoke and said driving shaft for relative longitudinal movement therebetween with change in angularity of said shaft. A

4. The combination with a tractor of a power take-off assembly for driving a trailing vehicle comprising a driven shaft connected to said vehicle, a driving shaft positioned on said tractor on a xed center of rotation, a pair of close coupled front and rear universal joints each having oppositely disposed yokes, a slidable driving connection between the front yoke of the iirst universal joint and said driving shaft, means for iixedly connecting the rear yoke of the rear universal joint to said driven shaft to transmit rotation between said driving and driven shafts with change of angularity therebetween, and means for supporting said joints for angular movement between said shafts comprising a bearing disposed in fixed relation longitudinally with respect to said driven yoke in all positions thereof, and means for supporting said bearing for rotation about two axes at right angles to each other with relative angular movements of said driving and driven shafts.

5. The combination with a tractor of a power take-oil assembly for driving a trailing vehicle comprising a driving shaft on said tractor, a driven shaft adapted for transmitting power drive for mechanism carried on the trailing vehicle, a pair of close coupled universal joints having a forward yoke for attachment to said driving shaft and a rearward yoke for attachment to said driven shaft, means iixedly attached to the tractor for supporting said rearward yoke to rotate on an arc of a circle about a fixed vertical axis with change in angularity of said shafts in a horizontal plane, a fixed driving connection between said rearward yoke and said driven shaft, a sliding driving connection between said forward yoke and said driving shaft for relative longitudinal movement therebetween with change in angularity of said shafts, and a bearing around said forward yoke to support the same for longitudinal movement.

6. The combination with a tractor of a power take-off assembly for driving a trailing vehicle comprising a driving shaft on said tractor, a pair of close coupled universal joints having a forward yoke for attachment to said driving shaft and a rearward yoke for attachment to a driven shaft, means iixedly attached to the tractor for supporting said rearward yoke to rotate on an arc of a circle about a fixed vertical axis with change in angularity of said shafts in a horizontal plane, a sliding driving connection between said forward yoke and said driving shaft for relative longitudinal movement therebetween with change in angularity of said shafts, a bearing on said forward yoke for imparting support thereto, and means for supportsleeve receiving said bearing therein for longifor reception of said driving shaft and spaced yoke arms, and a rearward yoke for attach ment to a driven shaft, means xedly attached to the tractor for supporting said rearward yoke to rotate on an arc of a circle about a fixed vertical axis with change in angularity of said shafts in a horizontal plane, a bearing on-said sleeve in close proximity to said yoke arms, and means for supporting' said bearing for longitudinal movement with said yoke to support the same against lateral movement.

8. The combination with a tractor of a power take-off assembly for driving a trailing vehicle comprising a splined driving shaft on said tractor, a pair of close coupled universal joints having a forward yoke including a splined sleeve for reception of said driving shaft and spaced yoke arms, and a rearward yoke for attachment to a driven shaft, means fixedly attached to the tractor for supporting said rearward yoke'to rotate on an arc of a circle about a fixed vertical axis with change in angularity of said shafts in a horizontal plane, a bearing on said sleeve in close proximity to said yoke arms, and a sleeve fixed on a stationary part of said tractor in concentric relationship with said yoke sleeve receiving said bearing therein for longitudinal movement with said yoke to support the latter for longitudinal movement.

9. The combination with a tractor of a power take-off assembly for driving a trailing vehicle comprising a splined driving shaft on said tractor, a pair of close coupled universal joints having a forward yoke including a splined sleeve for reception of said driving shaft and spaced yoke arms, and a rearward yoke for attachment to a driven shaft, means fixedly attached to the tractor for supporting said rearward yoke to rotate on an arc of a circle about a fixed verticalaxis with change in angularity of said shafts in a horizontal plane, a bearing on the sleeve of said forward yoke in close proximity to said yoke arms, a sleeve fixed on a stationary part of said tractor in concentric relationship with said yoke tudinal movement with said yoke to support the latter for longitudinal movement, and a seal disposed between said bearing and said fixed sleeve for preventing egress of lubricant and entrance of dirt.

10. The combination in a tractor of 4a power take-off assembly for driving atrailing vehicle comprising a driving shaft on said tractor, a driven shaft adapted for transmitting power drive for mechanism carried on the trailing vehicle, a pair of close coupled front and rear universal` joints, the first joint having a forward yoke for attachment to said driving shaft and the rear joint having a rearward yoke for attachment to said driven shaft, means fixedly attached to the tractor for supporting said reary ward yoke to rotate on an rarc of i a .circle about a fixed vertical axis with change in angularity of said shafts in a horizontal plane and also for rotation on a horizontal axis, said means comprising a support vmember around said driving shaft shaped for located reception against the frame of the tractor, said support member having rearwardly projecting arms disposed on opposite sides of said joints, a collar circumscrbing said rear joint and having forwardly disposed arms pivoted on the arms of said support for` rotation of said collar on a fixed axis,

a bearing for supporting said rear joint disposed in fixed relation longitudinally with respect to said rearward yoke, and means for pivotally supporting said bearing on said collar for rotation on an axis transverse to the axis of rotation of said collar, a fixed driving connection between said rearward yoke and said driven shaft, a sliding driving connection between said forward yoke and said driving shaft for relative longitudinal movement therebetween with change in angularity of said shafts, and a bearing around said forward yoke carried inv said support member to support said forward yoke for longitudinal movement on said driving shaft.

CARL E; SWENSON. 

